The present study constructs a remanufacturing supply chain framework that encompasses both manufacturer and retailer. We conduct an in-depth investigation into the influence exerted by blockchain platforms in the supply chain, in response to carbon reduction challenges initiated by manufacturers. By introducing parameters such as the proportion of joint emission reduction investment costs and blockchain unit verification fees, we perform a comprehensive analysis of the effects produced by consumer sensitivity and blockchain platforms on sales prices, recycling prices, carbon emission reduction, market demand, amount of recycled, and profits under different emission reduction modes. Research has revealed that irrespective of whether the manufacturer adopts blockchain platforms, wholesale prices, retail prices, carbon emission reduction, market demand, manufacturer's profit in the joint emission reduction model are always higher than those in individual emission reduction model, while recycling prices and amount of recycled remain unchanged. With retailer's share of the carbon reduction investment cost kept within an appropriate range, both profits of retailer and supply chain increase under joint emission reduction model. When a manufacturer introduces blockchain technology platforms, unit verification fees only affect wholesale prices and have no impact on retail prices, recycling prices, carbon emission reduction, and profits.

The management of recycling and remanufacturing supply chains, which can help enterprises achieve low pollution, low energy consumption and sustainable development, has become a new strategy of modern enterprises. The factors of supply chain and government mechanisms will have an impact on enterprise decisions for recycling, remanufacturing and social welfare. In order to promote the sustainable operation of the supply chain, considering the coordination role of government mechanisms and supply chain, a recycling and remanufacturing supply chain model composed of a manufacturer, retailer and recycler is constructed. This paper discusses the pricing decision of new/remanufactured products, supply chain performance level, such as remanufacturing effort, publicity service efforts and profit, and social welfare in five models of three situations: centralized situation, including non-government mechanisms and non-supply chain coordination; manufacturer-led situation, including non-government mechanisms and non-supply chain coordination, government mechanisms and non-supply chain coordination, government mechanisms and supply chain coordination; government-led situation, including government mechanisms and non-supply chain coordination. It is found that under manufacturer-led situations, the government subsidy and bonus-penalty mechanisms can encourage manufacturer and retailer to actively participate in the recycling and remanufacturing activities. The supply chain coordination contract can further enhance the role of the consumer market and promote the implementation of government mechanisms. Manufacturer adopts a cost-sharing contract to encourage recyclers to carry out recycling activities. Under certain conditions, the contract can effectively improve the benefits and social welfare. The research conclusions have important theoretical and practical application value for the coordination and cooperation among enterprises in the supply chain and the formulation of government mechanisms.