<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:9665bcd7-1824-4030-b2c2-da15ed0f9f86,g:803ad196-2067-47f2-9178-ef3245c71563-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:acnt="http://ascentco.com/20250930" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2024-01-31" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://ascentco.com/20250930">
  <xs:import namespace="http://fasb.org/srt/2025" schemaLocation="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap/2025" schemaLocation="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2024-01-31" schemaLocation="https://www.xbrl.org/dtr/type/2024-01-31/types.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/dei/2025" schemaLocation="https://xbrl.sec.gov/dei/2025/dei-2025.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/ecd/2025" schemaLocation="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="acnt-20250930_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="acnt-20250930_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="acnt-20250930_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="acnt-20250930_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="CoverPage" roleURI="http://ascentco.com/role/CoverPage">
        <link:definition>0000001 - Document - Cover Page</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedBalanceSheets" roleURI="http://ascentco.com/role/CondensedConsolidatedBalanceSheets">
        <link:definition>9952151 - Statement - Condensed Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedBalanceSheetsParenthetical" roleURI="http://ascentco.com/role/CondensedConsolidatedBalanceSheetsParenthetical">
        <link:definition>9952152 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsofIncomeLossUnaudited" roleURI="http://ascentco.com/role/CondensedConsolidatedStatementsofIncomeLossUnaudited">
        <link:definition>9952153 - Statement - Condensed Consolidated Statements of Income (Loss) (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsofCashFlowsUnaudited" roleURI="http://ascentco.com/role/CondensedConsolidatedStatementsofCashFlowsUnaudited">
        <link:definition>9952154 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsofShareholdersEquityUnaudited" roleURI="http://ascentco.com/role/CondensedConsolidatedStatementsofShareholdersEquityUnaudited">
        <link:definition>9952155 - Statement - Condensed Consolidated Statements of Shareholders' Equity (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsofShareholdersEquityUnauditedParenthetical" roleURI="http://ascentco.com/role/CondensedConsolidatedStatementsofShareholdersEquityUnauditedParenthetical">
        <link:definition>9952156 - Statement - Condensed Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BasisofPresentation" roleURI="http://ascentco.com/role/BasisofPresentation">
        <link:definition>9952157 - Disclosure - Basis of Presentation</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DiscontinuedOperations" roleURI="http://ascentco.com/role/DiscontinuedOperations">
        <link:definition>9952158 - Disclosure - Discontinued Operations</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenueRecognition" roleURI="http://ascentco.com/role/RevenueRecognition">
        <link:definition>9952159 - Disclosure - Revenue Recognition</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueofFinancialInstruments" roleURI="http://ascentco.com/role/FairValueofFinancialInstruments">
        <link:definition>9952160 - Disclosure - Fair Value of Financial Instruments</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Inventories" roleURI="http://ascentco.com/role/Inventories">
        <link:definition>9952161 - Disclosure - Inventories</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PropertyPlantandEquipment" roleURI="http://ascentco.com/role/PropertyPlantandEquipment">
        <link:definition>9952162 - Disclosure - Property, Plant and Equipment</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IntangibleAssetsandDeferredCharges" roleURI="http://ascentco.com/role/IntangibleAssetsandDeferredCharges">
        <link:definition>9952163 - Disclosure - Intangible Assets and Deferred Charges</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Debt" roleURI="http://ascentco.com/role/Debt">
        <link:definition>9952164 - Disclosure - Debt</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Leases" roleURI="http://ascentco.com/role/Leases">
        <link:definition>9952165 - Disclosure - Leases</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ShareholdersEquity" roleURI="http://ascentco.com/role/ShareholdersEquity">
        <link:definition>9952166 - Disclosure - Shareholders' Equity</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsPerShare" roleURI="http://ascentco.com/role/EarningsPerShare">
        <link:definition>9952167 - Disclosure - Earnings Per Share</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxes" roleURI="http://ascentco.com/role/IncomeTaxes">
        <link:definition>9952168 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsandContingencies" roleURI="http://ascentco.com/role/CommitmentsandContingencies">
        <link:definition>9952169 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IndustrySegments" roleURI="http://ascentco.com/role/IndustrySegments">
        <link:definition>9952170 - Disclosure - Industry Segments</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SubsequentEvents" roleURI="http://ascentco.com/role/SubsequentEvents">
        <link:definition>9952171 - Disclosure - Subsequent Events</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BasisofPresentationPolicies" roleURI="http://ascentco.com/role/BasisofPresentationPolicies">
        <link:definition>9955511 - Disclosure - Basis of Presentation (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DiscontinuedOperationsTables" roleURI="http://ascentco.com/role/DiscontinuedOperationsTables">
        <link:definition>9955512 - Disclosure - Discontinued Operations (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenueRecognitionTables" roleURI="http://ascentco.com/role/RevenueRecognitionTables">
        <link:definition>9955513 - Disclosure - Revenue Recognition (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InventoriesTables" roleURI="http://ascentco.com/role/InventoriesTables">
        <link:definition>9955514 - Disclosure - Inventories (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PropertyPlantandEquipmentTables" roleURI="http://ascentco.com/role/PropertyPlantandEquipmentTables">
        <link:definition>9955515 - Disclosure - Property, Plant and Equipment (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IntangibleAssetsandDeferredChargesTables" roleURI="http://ascentco.com/role/IntangibleAssetsandDeferredChargesTables">
        <link:definition>9955516 - Disclosure - Intangible Assets and Deferred Charges (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesTables" roleURI="http://ascentco.com/role/LeasesTables">
        <link:definition>9955517 - Disclosure - Leases (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ShareholdersEquityTables" roleURI="http://ascentco.com/role/ShareholdersEquityTables">
        <link:definition>9955518 - Disclosure - Shareholders' Equity (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsPerShareTables" roleURI="http://ascentco.com/role/EarningsPerShareTables">
        <link:definition>9955519 - Disclosure - Earnings Per Share (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesTables" roleURI="http://ascentco.com/role/IncomeTaxesTables">
        <link:definition>9955520 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IndustrySegmentsTables" roleURI="http://ascentco.com/role/IndustrySegmentsTables">
        <link:definition>9955521 - Disclosure - Industry Segments (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DiscontinuedOperationsNarrativeDetails" roleURI="http://ascentco.com/role/DiscontinuedOperationsNarrativeDetails">
        <link:definition>9955522 - Disclosure - Discontinued Operations - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DiscontinuedOperationsScheduleofAssetsandLiabilitiesDetails" roleURI="http://ascentco.com/role/DiscontinuedOperationsScheduleofAssetsandLiabilitiesDetails">
        <link:definition>9955523 - Disclosure - Discontinued Operations - Schedule of Assets and Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DiscontinuedOperationsScheduleofResultsofDiscontinuedOperationsDetails" roleURI="http://ascentco.com/role/DiscontinuedOperationsScheduleofResultsofDiscontinuedOperationsDetails">
        <link:definition>9955524 - Disclosure - Discontinued Operations - Schedule of Results of Discontinued Operations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenueRecognitionScheduleofDisaggregatedRevenuebyProductGroupDetails" roleURI="http://ascentco.com/role/RevenueRecognitionScheduleofDisaggregatedRevenuebyProductGroupDetails">
        <link:definition>9955525 - Disclosure - Revenue Recognition - Schedule of Disaggregated Revenue by Product Group (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenueRecognitionScheduleofRevenueRemainingPerformanceObligationExpectedTimingofSatisfactionDetails" roleURI="http://ascentco.com/role/RevenueRecognitionScheduleofRevenueRemainingPerformanceObligationExpectedTimingofSatisfactionDetails">
        <link:definition>9955526 - Disclosure - Revenue Recognition - Schedule of Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueofFinancialInstrumentsNarrativeDetails" roleURI="http://ascentco.com/role/FairValueofFinancialInstrumentsNarrativeDetails">
        <link:definition>9955527 - Disclosure - Fair Value of Financial Instruments - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InventoriesDetails" roleURI="http://ascentco.com/role/InventoriesDetails">
        <link:definition>9955528 - Disclosure - Inventories (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PropertyPlantandEquipmentDetails" roleURI="http://ascentco.com/role/PropertyPlantandEquipmentDetails">
        <link:definition>9955529 - Disclosure - Property, Plant and Equipment (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IntangibleAssetsandDeferredChargesNarrativeDetails" roleURI="http://ascentco.com/role/IntangibleAssetsandDeferredChargesNarrativeDetails">
        <link:definition>9955530 - Disclosure - Intangible Assets and Deferred Charges - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IntangibleAssetsandDeferredChargesScheduleofIntangibleAssetsDetails" roleURI="http://ascentco.com/role/IntangibleAssetsandDeferredChargesScheduleofIntangibleAssetsDetails">
        <link:definition>9955531 - Disclosure - Intangible Assets and Deferred Charges - Schedule of Intangible Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IntangibleAssetsandDeferredChargesScheduleofEstimatedAmortizationExpenseDetails" roleURI="http://ascentco.com/role/IntangibleAssetsandDeferredChargesScheduleofEstimatedAmortizationExpenseDetails">
        <link:definition>9955532 - Disclosure - Intangible Assets and Deferred Charges - Schedule of Estimated Amortization Expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IntangibleAssetsandDeferredChargesScheduleofDeferredChargesDetails" roleURI="http://ascentco.com/role/IntangibleAssetsandDeferredChargesScheduleofDeferredChargesDetails">
        <link:definition>9955533 - Disclosure - Intangible Assets and Deferred Charges - Schedule of Deferred Charges (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DebtNarrativeDetails" roleURI="http://ascentco.com/role/DebtNarrativeDetails">
        <link:definition>9955534 - Disclosure - Debt - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesNarrativeDetails" roleURI="http://ascentco.com/role/LeasesNarrativeDetails">
        <link:definition>9955535 - Disclosure - Leases - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesScheduleofOperatingandFinanceLeasesRecordedintheConsolidatedBalanceSheetDetails" roleURI="http://ascentco.com/role/LeasesScheduleofOperatingandFinanceLeasesRecordedintheConsolidatedBalanceSheetDetails">
        <link:definition>9955536 - Disclosure - Leases - Schedule of Operating and Finance Leases Recorded in the Consolidated Balance Sheet (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesScheduleofTotalLeaseCostDetails" roleURI="http://ascentco.com/role/LeasesScheduleofTotalLeaseCostDetails">
        <link:definition>9955537 - Disclosure - Leases - Schedule of Total Lease Cost (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesScheduleofFutureExpectedCashReceiptsFromSubleaseDetails" roleURI="http://ascentco.com/role/LeasesScheduleofFutureExpectedCashReceiptsFromSubleaseDetails">
        <link:definition>9955538 - Disclosure - Leases - Schedule of Future Expected Cash Receipts From Sublease (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesScheduleofMaturitiesofLeaseLiabilitiesDetails" roleURI="http://ascentco.com/role/LeasesScheduleofMaturitiesofLeaseLiabilitiesDetails">
        <link:definition>9955539 - Disclosure - Leases - Schedule of Maturities of Lease Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesScheduleofMaturitiesofLeaseLiabilitiesDetails_1" roleURI="http://ascentco.com/role/LeasesScheduleofMaturitiesofLeaseLiabilitiesDetails_1">
        <link:definition>9955539 - Disclosure - Leases - Schedule of Maturities of Lease Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesScheduleofWeightedAverageRemainingLeaseTermDetails" roleURI="http://ascentco.com/role/LeasesScheduleofWeightedAverageRemainingLeaseTermDetails">
        <link:definition>9955540 - Disclosure - Leases - Schedule of Weighted Average Remaining Lease Term (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ShareholdersEquityStockRepurchaseProgramDetails" roleURI="http://ascentco.com/role/ShareholdersEquityStockRepurchaseProgramDetails">
        <link:definition>9955541 - Disclosure - Shareholders' Equity - Stock Repurchase Program (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ShareholdersEquityScheduleofSharesRepurchasedDetails" roleURI="http://ascentco.com/role/ShareholdersEquityScheduleofSharesRepurchasedDetails">
        <link:definition>9955542 - Disclosure - Shareholders' Equity - Schedule of Shares Repurchased (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsPerShareDetails" roleURI="http://ascentco.com/role/EarningsPerShareDetails">
        <link:definition>9955543 - Disclosure - Earnings Per Share (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesDetails" roleURI="http://ascentco.com/role/IncomeTaxesDetails">
        <link:definition>9955544 - Disclosure - Income Taxes (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsandContingenciesDetails" roleURI="http://ascentco.com/role/CommitmentsandContingenciesDetails">
        <link:definition>9955545 - Disclosure - Commitments and Contingencies (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IndustrySegmentsNarrativeDetails" roleURI="http://ascentco.com/role/IndustrySegmentsNarrativeDetails">
        <link:definition>9955546 - Disclosure - Industry Segments - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IndustrySegmentsScheduleofSegmentInformationDetails" roleURI="http://ascentco.com/role/IndustrySegmentsScheduleofSegmentInformationDetails">
        <link:definition>9955547 - Disclosure - Industry Segments - Schedule of Segment Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="acnt_AdvancesAndOtherReceivablesCurrent" abstract="false" name="AdvancesAndOtherReceivablesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_DeferredChargesNetNoncurrent" abstract="false" name="DeferredChargesNetNoncurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_GainLossOnOperatingLeaseModification" abstract="false" name="GainLossOnOperatingLeaseModification" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_NetLossIncomePerCommonShareFromContinuingOperationsAbstract" abstract="true" name="NetLossIncomePerCommonShareFromContinuingOperationsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_NetIncomeLossPerCommonShareFromDiscontinuedOperationsAbstract" abstract="true" name="NetIncomeLossPerCommonShareFromDiscontinuedOperationsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_NetLossIncomePerCommonShareAbstract" abstract="true" name="NetLossIncomePerCommonShareAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_IntangibleAssetsAndDeferredChargesTextBlock" abstract="false" name="IntangibleAssetsAndDeferredChargesTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="acnt_AssetsAndLiabilitiesLesseeTableTextBlock" abstract="false" name="AssetsAndLiabilitiesLesseeTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="acnt_BristolMetalsLLCMember" abstract="true" name="BristolMetalsLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_AmericanStainlessTubingLLCMember" abstract="true" name="AmericanStainlessTubingLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_EscrowDepositPaymentPeriod" abstract="false" name="EscrowDepositPaymentPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="acnt_DisposalGroupIncludingDiscontinuedOperationRightOfUseAssets" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationRightOfUseAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilityCurrent" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilityCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_DisposalGroupIncludingDiscontinuedOperationFinanceLeaseLiabilityCurrent" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationFinanceLeaseLiabilityCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_DisposalGroupIncludingDiscontinuedOperationAcquisitionCostsAndOther" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationAcquisitionCostsAndOther" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_DisposalGroupIncludingDiscontinuedOperationAssetImpairmentCharges" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationAssetImpairmentCharges" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_CustomManufacturingMember" abstract="true" name="CustomManufacturingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_ProductInnovationSalesMember" abstract="true" name="ProductInnovationSalesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_MunhallFacilityMember" abstract="true" name="MunhallFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_DeferredChargesAmortizationPeriod" abstract="false" name="DeferredChargesAmortizationPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="acnt_TheFacilityMember" abstract="true" name="TheFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_ABLLineOfCreditDueJanuary152025Member" abstract="true" name="ABLLineOfCreditDueJanuary152025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_LineOfCreditFacilityCovenantMinimumAmountOfAvailabilityRequired" abstract="false" name="LineOfCreditFacilityCovenantMinimumAmountOfAvailabilityRequired" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_LineOfCreditFacilityCovenantRequiredPercentage" abstract="false" name="LineOfCreditFacilityCovenantRequiredPercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acnt_FifthAmendedAndRestatedMasterLeaseAgreementMember" abstract="true" name="FifthAmendedAndRestatedMasterLeaseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_SixthAmendedAndRestatedMasterLeaseAgreementMember" abstract="true" name="SixthAmendedAndRestatedMasterLeaseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_IncreaseDecreaseInOperatingLeaseRightOfUseAsset" abstract="false" name="IncreaseDecreaseInOperatingLeaseRightOfUseAsset" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_SaleLeasebackTransactionOperatingLeaseLiability" abstract="false" name="SaleLeasebackTransactionOperatingLeaseLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_SaleLeasebackTransactionOperatingLeaseLiabilityPercentOfTotalOperatingLeaseLiabilities" abstract="false" name="SaleLeasebackTransactionOperatingLeaseLiabilityPercentOfTotalOperatingLeaseLiabilities" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acnt_SubleaseReceiptsAbstract" abstract="true" name="SubleaseReceiptsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_LessorOperatingLeasePaymentToBeReceivedAfterYearFour" abstract="false" name="LessorOperatingLeasePaymentToBeReceivedAfterYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour" abstract="false" name="LesseeOperatingLeaseLiabilityToBePaidAfterYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_FinanceLeaseLiabilityToBePaidAfterYearFour" abstract="false" name="FinanceLeaseLiabilityToBePaidAfterYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_WeightedAverageRemainingLeaseTermAbstract" abstract="true" name="WeightedAverageRemainingLeaseTermAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_LeasesWeightedAverageDiscountRateAbstract" abstract="true" name="LeasesWeightedAverageDiscountRateAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_AmendedShareRepurchaseProgramMember" abstract="true" name="AmendedShareRepurchaseProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_StockRepurchaseProgramTerm" abstract="false" name="StockRepurchaseProgramTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="acnt_EarningsPerShareNumeratorAbstract" abstract="true" name="EarningsPerShareNumeratorAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_EarningsPerShareDenominatorAbstract" abstract="true" name="EarningsPerShareDenominatorAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_EarningsPerShareBasicAndDilutedAbstractAbstract" abstract="true" name="EarningsPerShareBasicAndDilutedAbstractAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acnt_EffectiveIncomeTaxExcludingImpactOfDiscontinuedOperation" abstract="false" name="EffectiveIncomeTaxExcludingImpactOfDiscontinuedOperation" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acnt_SpecialtyChemicalsSegmentMember" abstract="true" name="SpecialtyChemicalsSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acnt_CostOfOtherMaterialAdjusted" abstract="false" name="CostOfOtherMaterialAdjusted" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acnt_OtherOperatingAndNonoperatingIncomeExpense" abstract="false" name="OtherOperatingAndNonoperatingIncomeExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
