Calumet adding pretreatment plant to Montana renewable diesel project By admin Posted June 9, 2021 In In the News Calumet adding pretreatment plant to Montana renewable diesel project2021-06-092021-06-09/wp-content/uploads/liberty-petroleum-icon-logo2.pngLiberty Petroleum Corp/wp-content/uploads/liberty-petroleum-icon-logo2.png200px200px Calumet Specialty Partners is adding a pretreatment plant to its renewable diesel project at its…