Decades　of　research　unveiled　the　unlimited　potential　of　metal-organic　frameworks　(MOFs).　Nevertheless,　the　hazardous　and　expensive　production　involving　massive　amounts　of　organic　solvents　has　severely　limited　their　widespread　industrial　adoption.　Herein,　the　advantages　of　two　eco-friendly　strategies,　base-assisted　synthesis　and　modulated　hydrothermal　chemistry,　were　complementarily　integrated,　with　the　acetate　anion　introduced　as　a　mild　and　efficacious　modulator　to　regulate　the　coordination　and　tailor　the　crystallization　pathway(s).　The　green,　rapid,　and　scalable　synthesis　of　a　dual-ligand　Zn-MOF　was　thereby　achieved　in　water　media,　featuring　an　unprecedented　space-time　yield　of　24　ton　per　m(3)　per　day　and　a　batch　size　exceeding　a　kilogram　(i.e.,　1.2　kg).　Owing　to　its　strong　affinity　toward　CH4,　the　acquired　Zn-MOF　demonstrated　a　considerable　CH4/N-2　separation　capacity　under　ambient　conditions.　This　study　not　only　facilitates　the　green　and　scalable　production　of　MOFs　but　also　offers　a　cost-effective　adsorbent　for　CH4　recovery.