Walnut　oil　production　waste　(WOPW)　is　a　by-product　of　walnut　oil　processing.　The　organic　waste　is　rich　in　holocellulose　and　lignin,　showing　good　potential　to　be　converted　by　thermal　process　to　valuable　products.　Superheated　steam　(SHS)　torrefaction　is　a　recently　proposed　thermal　process　enabling　fast　and　unformal　biomass　heating,　resulting　in　high-quality　solid　products　as　direct　fuel.　The　potential　of　SHS　to　torrefy　lipids　and　proteins　(being　rich　in　WOPW)　is　attractive　for　broader　application　of　SHS　torrefaction　to　upgrade　more　biomass　wastes.　SHS　torrefaction　was　studied　in　this　work　to　upgrade　WOPW　for　solid　products　with　different　reaction　temperatures　(200,　250,　300　°C)　and　residence　times　(20,　40,　60　min).　The　lowest　weight　yield　was　43.64　wt%　under　the　severest　treatment　of　300　°C　and　60　min,　accompanied　with　the　highest　energy　enhancement　of　1.34　(reaching　HHV　of　27.03　MJ/kg).　Response　surface　method　is　employed　to　reveal　the　effects　of　temperature　and　residence　time.　Residence　time　of　40　min　under　300　°C　was　supposed　to　be　an　ideal　condition　to　upgrade　WOPW　with　HHV　of　26.68　MJ/kg　and　in　the　range　of　coal　from　Van　Krevelen　diagram.　Combustion　indices　(e.g.,　fuel　ratio,　combustion　index,　and　volatile　ignitability)　indicated　that　the　aforementioned　torrefied　WOPW　had　favourable　properties　as　co-firing　material.　On　the　other　hand,　combustion　behaviours　analysis　demonstrated　that　SHS　torrefied　WOPW　could　perform　well　as　direct　fuel.　Aqueous　effluent　was　also　condensed　and　analyzed,　where　products　from　lipids　and　proteins　were　massively　presented,　giving　an　insight　into　the　decomposition　of　those　two　constitutes　undergoing　SHS　torrefaction.　©　2022　Elsevier　B.V.