Economy of scale implies that the capital cost per unit production in smaller-scale plants is higher than in large-scale production plants. A conceptual design for a scaled-down Fischer-Tropsch (FT) reactor is described and key performance indicators are determined and compared with those of large-scale FT reactors. The designed scaled-down FT reactor provides the petroleum and hydrocarbon waste processing sectors with a low-cost and low-risk gas-to-liquid technology for monetizing small-size gas sources. An option for achieving a high conversion of syngas reactants with single-pass operation makes it suitable for processing the associated gas that is usually flared at oil exploration and production sites.